Communication Service Providers are deploying a large number of Ethernet and IP services across networks and across a large number of Network Equipment Manufacturers (NEMS).
The support for Ethernet test and turn-up functions differs largely from one network equipment provider to another and this dramatically increases the operational complexity of deploying Ethernet based services across networks and across equipment vendors.
Network Elements (NEs) in today's networks are owned and managed by many parties that have interests in different portions of the Ethernet networks. To support the different needs of these parties, different types of services are being deployed over these networks.
One type of service being deployed is Ethernet Virtual Connections (EVCs). EVCs are logical representations of Ethernet services as defined by associations between 2 or more physical interfaces. EVCs may be deployed to differentiate traffic on Ethernet networks.
When a telecommunications service provider offers a Metro Ethernet service that is compliant with the Metro Ethernet Forum (MEF) specifications, the service has two basic elements: the UNI or ENNI (External Network to Network Interface) by which the service is provided to the customer, and an EVC that establishes a communication relationship between one or more UNIs or ENNIs. In Metro Ethernet services, there are three types of EVC: point-to-point, multipoint-to-multipoint and point-to-multipoint. Another type of service being deployed over Ethernet networks includes transporting traffic at different network layers such as Layer 2 (Ethernet frames) and Layer 3 (IP packets).
When test features are not implemented inside existing networking equipment, external Network Interface Devices (NIDs) or traffic generation equipment is inserted in-between equipment or attached to ports designated for these testing functions. These testing methods have significant drawbacks as they require extra equipment; extra rack space, extra cost and these additional pieces of equipment may introduce additional networking issues.
FIG. 1 illustrates how testing functions are typically implemented in prior art networks. In FIG. 1, heterogeneous NEs 2, 4, 6, 8, which may be provided by different manufacturers and may significantly differ from each other in capabilities, are connected in a network 5 such as by fiber optical cabling. The NEs 2, 4, 6, 8 have ports to receive transceivers 12, which provide electro-optical interfaces between NEs 2, 4, 6, 8 over the network 5. Some NEs, such as NE_A 2, have testing capability 11 and some do not, such as NE_B, NE_C and NE_D. Accordingly, NIDs 36, 38 have been added to provide additional test functions in a network between NE_B and NE_C. Certain parts of the network either cannot be covered or would be difficult to cover with test functions, such as NE_D 8 that is located in a constrained location 20 where no NID box or Network test equipment can be added. For example, adding NIDs near NE_D, which may be located in a wireless access tower, may not be possible due to physical constraints or other location restrictions.
NE_A 2 adds cost to the network 5 and additionally occupies a dedicated port on NE_B, which potentially reduces the amount of revenue from services the network operator can generate. While NE_A 2 and NIDs 36, 38 implement test functions, they also may not have the same management interface thus making them more difficult to use and maintain.
In the example in FIG. 1, installing NIDs 36, 38 is possible between NE_B 4 and NE_C 6 because, for example, the network administrator has access to the cabling between those two NEs and can physically interrupt those lines, install and manage additional NIDs. However, in FIG. 1, there are no NIDs between NE_C 6 and NE_D 8 because, for example, NE_D 8 may be located in the constrained location 20 where no NIDs could be added. In many cases, certain parts of the Ethernet network 5 cannot be covered, or would be excessively difficult to cover with test functions by the addition of NIDs due to physical constraints, such as NEs that are poles. As a result, it is common for the test functionality 11 to be unavailable in parts of the network 5. Although NE_A 2 and the NIDs 36, 38 implement test function 11, it is common that they do not share the same management interface making managing all of the network test functions difficult and disconnected.
Accordingly, prior art communication networks typically include segments that are not covered by necessary test functions and those that are covered have additional expenses associated with them. It would be advantageous to have a simple, cost effective and unified way to add Layer 2, Layer 3 and higher Layer testing functionalities on existing network equipments.